Siemens SIRIUS 3RW4447-6BC44 Soft Starter

The 3RW4447-6BC44 represents Siemens' advanced motor control technology for industrial applications. This SIRIUS soft starter delivers smooth acceleration and deceleration for three-phase motors. It significantly reduces mechanical stress and extends equipment lifespan.

Core Technical Specifications

• Brand: Siemens
• Model: 3RW4447-6BC44
• Product Line: SIRIUS Soft Starters
• Rated Current: 432A @ 40°C standard circuit
• Inside-Delta Current: 748A @ 40°C
• Motor Power: 250kW standard, 400kW inside-delta
• Operating Voltage: 200-460V AC
• Control Voltage: 230V AC
• Frequency Range: 50-60Hz ±10%
• Dimensions: 432 x 348 x 366 mm
• Weight: 11.53 kg
• Protection Class: IP00
• Ambient Temperature: -25°C to +60°C
• Installation Height: Up to 5000 meters
• Cable Length: Maximum 500 meters

Performance Characteristics

• The starter provides adjustable current limitation from 86A to 432A.
• It features integrated thermal motor overload protection with PTC evaluation.
• Built-in thyristors ensure reliable power control and smooth operation.
• The device offers 115% continuous operating current capability at 40°C.
• Automatic internal bypass contact reduces power loss during run state.
• Three normally open and one changeover auxiliary contacts enable control.
• LED display provides clear fault indication and status monitoring.
• External reset capability allows for remote system initialization.

Electrical Connections & Installation

• Main circuit connections utilize robust busbar termination system.
• Front terminals accept 70-240mm² fine-stranded cables with ferrules.
• Rear terminals accommodate 120-185mm² cables for flexible wiring.
• Combined clamping points handle up to 2x185mm² parallel conductors.
• Auxiliary circuits use screw terminals for 0.5-2.5mm² conductors.
• Maintain 100mm clearance above unit and 75mm below for ventilation.
• Side clearance of 5mm ensures proper air circulation and heat dissipation.
• Mounting position allows ±90° rotation and ±22.5° forward/backward tilt.

Motor Power Ratings

• Standard circuit delivers 250kW at 400V for three-phase motors.
• Inside-delta configuration provides 400kW at 400V operation.
• At 230V standard circuit, output power reaches 132kW.
• Horsepower ratings range from 125HP to 600HP depending on configuration.
• The starter handles minimum motor loads as low as 8% of rated current.
• Power loss during operation typically measures only 232 watts.
• Derating begins at 40°C ambient temperature for optimal performance.
• Current capacity decreases to 385A at 50°C and 335A at 60°C.

Protection & Safety Features

• Integrated electronic overload protection prevents motor damage.
• Thermal resistor monitoring provides additional motor protection.
• Phase failure detection ensures three-phase operation integrity.
• Current imbalance protection safeguards against uneven loading.
• Short-circuit protection built into the power electronics section.
• Undervoltage and overvoltage protection maintains system stability.
• Earth fault detection available through additional monitoring systems.
• UL/CSA certifications ensure compliance with international standards.

Packaging & Shipping

• Each unit ships in protective packaging with adequate cushioning.
• Package includes one soft starter unit ready for installation.
• We ship worldwide via FedEx, UPS, and DHL express services.
• Tracking information becomes available immediately after dispatch.
• All products include comprehensive 12-month warranty coverage.
• Most orders process within 24 hours of payment confirmation.

Professional Technical FAQ

• What is the difference between standard and inside-delta connection?
• Inside-delta connection allows higher current handling up to 748A for larger motors.
• Can this soft starter operate at high altitude locations?
• Yes, it maintains full performance up to 5000 meters above sea level.
• What type of motor protection does this unit provide?
• It includes electronic overload, thermal monitoring, and phase failure protection.
• How many auxiliary contacts are available for control circuits?
• The unit provides three NO contacts and one changeover contact for signaling.
• What is the recommended derating above 40°C ambient temperature?
• Current capacity reduces to 385A at 50°C and 335A at 60°C for safe operation.

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